Fluid heater by-pass tee

ABSTRACT

An improved tee shaped fitting for the heating system of a swimming pool. The fitting includes a water inlet and outlet aligned on a common axis and a bifurcated passage joined perpendicular to the axis of the inlet and outlet. The bifurcated passage includes first and second channels defined by a vane, the first channel being connected to the inlet, the second channel being connected with the outlet. The vane extends into the inlet and diverts only a portion of fluid through the first channel to a water heater. The second channel directs water to the outlet where it commingles with the fluid which flows past the diverting vane.

United States Patent Daughirda 51 Aug. 22, 1972 [54] FLUID HEATER BY-PASS TEE [72] Inventor: Paul G. Daughirda, Chicago, Ill.

[73] Assignee: Rheem Manufacturing Company [22] Filed: Nov. 6, 1970 [21] Appl. No.: 87,426

[52] US. Cl ..l37/599.l, 237/59 [51] Int. Cl 3/00 [58] Field of Search ..l3'7/599. l, 560; 237/59 [56] References Cited UNITED STATES PATENTS FOREIGN PATENTS OR APPLICATIONS 1,022,413 3/1966 Great Britain ..237/59 8/1917 Gilbert ..237/59 UX- Primary ExaminerAlan Cohan Att0meyMolinare, Allegretti, Newitt & Witcoff [57] ABSTRACT An improved tee'shaped fitting for the heating system of a swimming pool. The fitting includes a water inlet and outlet aligned on a common axis and a bifurcated passage joined perpendicular to the axis of the inlet and outlet. The bifurcated passage includes first and second channels defined by a vane, the first channel being connected to the inlet, the second channel being connected with the outlet. The 'vane extends into the 1 inlet and diverts only a portion of fluid through the first vchannel to a water heater. The second channel directs water to the outlet where it commingles with the fluid which flows past the diverting vane.

5 Clains, 3 Drawing Figures Patented Aug. 22, 1972 3,585,542

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% {ME-y 1 .WEN TOR; PAUL G. DAUGIRDA ATT'YS BACKGROUND OF THE INVENTION This invention relates to an improved plumbing fitting and more particularly to a device for bypassing a portion of flowing fluid that would normally flow through a fluid heater.

In a swimming pool filtration system, water is typically circulated through filtering and chemical treating means so that all the water in the pool is continuously treated. Heating the swimming pool water, while considered a luxury in the past, has now become common. As with filtering and chemical treating of pool water, all the water of the system is passed through a water heater. The large amount of water to be heated results in a relatively low water temperature in the heater, that is below 80 to 90 F. This low water heater temperature permits condensation from the heater flue products to accumulate within the heating unit and corrode the heater parts.

An alternative to continuously heating all of the poo water incorporates a fluid heater bypass made from standard pipe fittings. This bypass arrangement diverts a portion of the water to the heater. The heated water is later mixed with the unheated water for addition to the pool. This construction also provides flue product condensation which tends to corrode the heating unit.

Both of the above described means for heating water for a swimming pool call for extensive and expensive plumbing and piping, and, on occasion, necessary replacement of corroded heater parts.

SUMMARY OF THE INVENTION In a principal aspect the present invention comprises an improved fitting, particularly useful with a system for heating swimming pool water. The fitting diverts a portion of fluid from a main flow and directs the diverted portion through a heater. The diverted water is heated to a temperature sufficient to maintain flowing fluid temperatures above the dew point of flue products. This eliminates condensation of the flue products and thereby eliminates corrosion of the heating units.

It is therefore an object of this invention to provide a simple and economical apparatus or fitting for diverting an amount of fluid to a heating tank.

It is another object to provide a unitary maintenancefree by-pass device for use in a flowing fluid heating system.

A further object is to provide an improved fitting adaptable to standard piping systems without requiring complicated pipe adapters or extensive additional plumbing for installation.

It is also an object of this invention to provide a fitting which includes means to measure the temperature of an inlet flow of fluid and an outlet flow of heated fluid.

It is another object of this invention to provide a fitting which may be used in combination wit a pool heating system to maintain a diverted flow of fluid above the dew point of the flue products of the heating means and thereby eliminate condensation of flue products and corrosion of the heating units.

Another object of the present invention is to provide means for diverting a selected amount of fluid for heating or the like and also to provide means for commingling selected amounts of undiverted fluid and heated fluid.

These and other objects and advantages will become more apparent in the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS Particular embodiments of the present invention are illustrated in the accompanying drawings wherein:

FIG. 1 is a front view of the improved fitting of the invention as it would typically be mounted on a tank type heater.

FIG. 2 is a cross-sectional plan view of the fitting shown in FIG. 1 taken along line 2-2 of FIG. 1.

FIG. 3 is a cross-sectional plan view taken of the fitting as shown in FIG. 2 taken along line 3-3 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, FIG. 1 shows the teeshaped fitting 10 mounted substantially near the top of a heater tank 12.- Flue exhaust duct 14 shown on top of the heater tank 12 is used to exhaust combustion products from a gas fired burner associated with the tank 12. In some prior art pool heating systems all the circulating water would pass through the filtration system, chemical treating systems and ultimately the heating system. By heating all of the circulating pool water, the temperature of the heating tank was normally below the range of to F. This low temperature of the heating tank resulted in condensation of the flue products as they traveled out the duct 14. Condensation in duct 14 resulted in its corrosion and ultimately the corrosion spread to the heater tank 12 causing failure of the heating system.

The present invention acts to divert a portion of the circulating fluid to the heater means. The water is therefore heated to a temperature above the dew point of exhaust flue products and consequently, theinternal flue of the tank type heater may now be maintained at a temperature sufficiently high enough to prevent the condensation of the flue products. The heated fluid is then commingled with the undiverted circulating fluid. Details of the by-pass tee of the present invention are shown in greater detail in FIGS. 2 and 3 which illustrate cross-sectional views of the tee or fitting.

The fitting 10 includes an inlet opening 16 and an outlet opening 18 in coaxial alignment. The fitting as illustrated in FIGS. 2 and 3 has openings 16 and 18 of equal inner diameters. It is possible to vary the diameters of the passages and/or openings depending upon the particular application and the amount of water which is to be diverted.

Openings 16 and 18 are connected with perpendicular bifurcated passage 20. The end of the passage 20 has standard pipe threads as do the inlet 16 and outlet 18. Such threading allows adaptation of fitting 10 with troduced to the tank 12 is colder than the stored water I in the tank 12, it falls to the lower portion of the tank 12. Vane extension 28 prevents a short circuit in the tank 12 of the flowing water. That is, extension 28 prevents the cold water from entering the tank via channel 22 and then immediately exiting through channel 24. The sides of the vane 26 are planar. However,

the sides of vane 26 may be of any desired shape. For

,example, the sides of vane 26 defining channels 22 and 24 can be concave in shape to give the channels a substantially circular cross-section. In either event, the thickness of the vane is kept at a minimum as compared to the inlet opening 16 to avoid impeding the incoming flow of fluid. Typically, the thickness of the vane 26 is no more than 1/12 the diameter of inlet 16. While the leading edge of the vane 26 is shown as rounded, it is to be understood the edge can be pointed so as to decrease any resistance to fluid flow.

FIG. 3 shows the vane 26 extending into the inlet opening 16 to divert the flowing water. Water flow is indicated by thearrows. The radius of curvature of the vane extension into inlet 16 may vary from A; to 1 inch depending upon diversion requirements and the distance which the vane 26 extends into passage 16. While the figure illustrates the vane 26 extending to a point on the coaxial centerline axis between inlet 16 and outlet 18 with a diversion of approximately onehalf of the incoming water, it is not intended that the invention be so limited. The vane 26 can be located to divert different amounts of fluid. For example, the swimming pool size normally is determinative of the gallons per minute flow rate of water. Municipal systems require certain legal minimum flow rates. To maintain a given flow and a fixed average outlet temperature of fluid discharged from outlet 18, the temperature and amount of heated water flowing through passage 24 must be controlled. This, in turn, is dependent upon the amount of water being diverted through passage 22 into the tank 12 as well as the heating capacity of the tank 12 and the relative sizes of passages 22 and 24. Thus the amount of water diverted depends on the particular application. Set forth in tabu- -lar form below is data regarding the correlation between the fluid flow and the position of the vane in the by-pass tee.

X/D Ratio of Dimensions Diversion of Fluid 6 in FIG. 3 Through Passage 22 Thus, knowing the required outlet flow rate and the heating capacity of the tank 12 one can calculate the desired fitting of the present invention required for a particular application by utilizing data from the above table.

Pool aquastat or water temperature control sensing elements 30.and 32 may also be placed in the channels 22 and 24 respectively as shown in FIGS. The elements are mounted by 'known water-tight means and extend through the wall of the fitting into the channels .22 and 24. Element 32 extends the length of channel24 and into the water heater tank 12. Element extends through an aperture-27 in vane 26 and into channel 22 where it senses the water temperature of the diverted flow of water.

The sensing elements are connected to control means of the gas burners associated with the water heater. When the temperature of. incoming water is below a desired level, the burners are ignited. The element 32 senses the temperature of the water inthe tank' and operates means to extinguish or ignite the gas burners. For example, if there is an overheating situation the burners are extinguished. If the water temperature is below a desired level the burners are ignited. Typically, the water is heated to a temperature of 150 to 200 F. before passing through passage 24 and commingling with the unheated water. An important factor to keep in mind is that the water temperature in the tank 12 should be higher than the dew point of the heater combustion products. It is to be understood the sensing elements are kept to a minimum diameter so as not to impede the diverted incoming fluid flow. A

device such as the Robertshaw RT HMV Aquastat has been found to operate effectively.

While in the foregoing there has been provided a detailed description of a particular embodiment of the present invention, it is to be understood that all equivalents obvious to those having skill in the art are to be included within the scope of the invention as claimed including equivalent constructions for purposes other than being included as part of a water heating system and constructions having shapes other than a tee shape.

What is claimed is:

1. In combination with a water tank of a water heater system, an improved fitting comprising: a T-shaped fitting'having a bifurcated passage comprised of first and second channels, a fluid-inlet,-a fluid outlet connected to said inlet, said first channel being connected to said inlet and said second channel being connected with said outlet, said passage including a fluid flowv diverting vane extending along said passage to define said channels, said vane extending into said inlet to divert a portion of fluid flowing into said inlet through said first channel into said tank, the remainder of fluid flowing into said inlet flowing directlyto said outlet and commingling with fluid flowing from said second channel to said outlet, and temperature sensitive control means in said channels to measure water temperature in said first channel, and to also measure water temperature in said tank.

2. The improved fitting of claim 1 wherein said temperature sensitive means includes a device extending from said second channel into said tank to sense the temperature of fluid flowing into said second channel for admixing with fluid from said inlet.

radius of curvature from 1/8 inch to 1 inch and wherein the thickness of said vane is no more than 1/12 the diameter of the inlet opening.

5. The improved fitting of claim 1 wherein the leading edge of said vane extending into the inlet is rounded. 

1. In combination with a water tank of a water heater system, an improved fitting comprising: a T-shaped fitting having a bifurcated passage comprised of first and second channels, a fluid inlet, a fluid outlet connected to said inlet, said first channel being connected with said inlet and said second channel being connected with said outlet, said passage including a fluid flow diverting vane extending along said passage to define said channels, said vane extending into said inlet to divert a portion of fluid flowing into said inlet through said first channel into said tank, the remainder of fluid flowing into said inlet flowing directly to said outlet and commingling with fluid flowing from said second channel to said outlet, and temperature sensitive control means in said channels to measure water temperature in said first channel, and to also measure water temperature in said tank.
 2. The improved fitting of claim 1 wherein said temperature sensitive means includes a device extending from said second channel into said tank to sense the temperature of fluid flowing into said second channel for admixing with fluid from said inlet.
 3. The improved fitting of claim 1 wherein said vane extends into said tank to prevent short circuiting of fluid from said first channel into said second channel.
 4. The improved fitting of claim 1 wherein said vane has planar sides, is arcuately shaped and extends from a point on a line parallel to said flow of fluid into said inlet, to a position substantially parallel to the centerline of said bifurcated passage, said arcuate vane having a radius of curvature from 1/8 inch to 1 inch and wherein the thickness of said vane is no more than 1/12 the diameter of the inlet opening.
 5. The improved fitting of claim 1 wherein the leading edge of said vane extending into the inlet is rounded. 